Internal combustion engine



FIG. 1 is a perspective view of an internal combustion engine embodying our design; as viewed from the front thereof;

FIG. 2 is a perspective view of the internal combustion engine as viewed from its rear;

FIG. 3 is a front elevational view of FIG. 1;

FIG. 4 is a rear elevational view of FIG. 1;

FIG. 5 is a left side elevational view of FIG. 1;

FIG. 6 is a right side elevational view of FIG. 1;

FIG. 7 is a top plan view of FIG. 1; and,

FIG. 8 is a bottom plan view of FIG. 1. 

The ornamental design for an internal combustion engine, as shown. 